Xu Yanqi, Xuan Weimin, Zhang Mengmeng, Miras Haralampos N, Song Yu-Fei
State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, P. R. China.
WestCHEM, School of Chemistry, University of Glasgow, University Avenue, Glasgow, G12 8QQ, UK.
Dalton Trans. 2016 Dec 6;45(48):19511-19518. doi: 10.1039/c6dt03445d.
Deep desulfurization is a challenging task and global efforts are focused on the development of new approaches for the reduction of sulfur-containing compounds in fuel oils. In this work, we have proposed a new design strategy for the development of deep desulfurization heterogeneous catalysts. Based on the adopted design strategy, a novel composite material of polyoxometalate (POM)-based ionic liquid-grafted layered double hydroxides (LDHs) was synthesized by an exfoliation/grafting/assembly process. The structural properties of the as-prepared catalyst were characterized using FT-IR, XRD, TG, NMR, XPS, BET, SEM and HRTEM. The heterogeneous catalyst exhibited high activity in deep desulfurization of DBT (dibenzothiophene), 4,6-DMDBT (4,6-dimethyldibenzothiophene) and BT (benzothiophene) at 70 °C in 25, 30 and 40 minutes, respectively. The catalyst can be easily recovered and reused at least ten times without obvious decrease of its catalytic activity. Such excellent sulfur removal ability as well as the cost efficiency of the novel heterogeneous catalyst can be attributed to the rational design, where the spatial proximity of the substrate and the active sites, the immobilization of ionic liquid onto the LDHs via covalent bonding and the recyclability of the catalyst are carefully considered.
深度脱硫是一项具有挑战性的任务，全球都致力于开发新方法以减少燃料油中的含硫化合物。在这项工作中，我们提出了一种用于开发深度脱硫多相催化剂的新设计策略。基于所采用的设计策略，通过剥离/接枝/组装过程合成了一种基于多金属氧酸盐（POM）的离子液体接枝层状双氢氧化物（LDHs）的新型复合材料。使用傅里叶变换红外光谱（FT-IR）、X射线衍射（XRD）、热重分析（TG）、核磁共振（NMR）、X射线光电子能谱（XPS）、比表面积分析（BET）、扫描电子显微镜（SEM）和高分辨率透射电子显微镜（HRTEM）对所制备催化剂的结构性质进行了表征。该多相催化剂在70℃下对二苯并噻吩（DBT）、4,6-二甲基二苯并噻吩（4,6-DMDBT）和苯并噻吩（BT）的深度脱硫中分别在25、30和40分钟内表现出高活性。该催化剂可以很容易地回收并重复使用至少十次，而其催化活性没有明显下降。这种新型多相催化剂优异的脱硫能力以及成本效益可归因于合理的设计，其中仔细考虑了底物与活性位点的空间接近性、离子液体通过共价键固定在层状双氢氧化物上以及催化剂的可回收性。
